Self-sealing container



Dec. 12 1967 c M. STANFORTH SELF-SEALING CONTAINER Filed Sept.

p F Wm 7: 2 5 2 4 a 5L f \1- C J f v z n n a h 4 H n E m m a m M V wUnited States Patent 3,357,632 SELF-SEALING CONTAINER Charles M.Stanforth, Cincinnati, Ohio, assignor to General Electric Company, acorporation of New York Filed Sept. 26, 1966, Ser. No. 581,806 Claims.(Cl. 22962.5)

ABSTRACT OF THE DISCLOSURE The disclosure shows a container formed bytwo layers of flexible polyethylene terephthalate sheet material joinedtogether by seamed portions which define an expansible storage chamberand an inlet passageway. The inlet passageway is elongated and defined,at least in part, by a seamed portion of the sheet material which alsodefines on its opposite side the storage chamber. The container isfilled by inserting a tube through the inlet passageway. Pressurized gasfrom the tube inflates the storage chamber. When the tube is withdrawn,the inlet passageway is self sealing.

The present invention relates to improvements in fluid containers and,more particularly, to improvements in containers for collecting andstoring gas samples.

There are many situations where it is desired to collect a gas sampleand then carry it to a remotely-located analyzer, such as a gaschromatograph, for an accurate determination of the constituentcomponents thereof. In order that the integrity of the gas sample bepreserved between the time of its collection and the analysis thereof,it has become an accepted practice to employ glass, or other similarinert material, containers for collecting or receiving and then storingsuch gas samples for later analysis. Not only does this involve arelatively large investment in the containers, it also entails aconsiderable expense in washing or cleaning the containers after eachuse so that subsequent samples will not be adulterated by traces of theprevious sample.

Not only these specialized containers but, in a broader sense, allcontainers for fluid storage usually require a closure which representsa substantial portion of the container cost. In the case of gas-storingcontainers, this is a further problem in that it is desirable to have aclosure of the so-called self-sealing type, i.e., a closure whichautomatically seals itself, after a gas sample has been introduced intothe container, without requiring manipulation of a cap or valve elementto obtain the sealing action.

Accordingly, one object of the invention is to provide an improved andparticularly inexpensive fluid container having a closure of theself-sealing type.

Another object of the invention is to provide such a container which isparticularly adapted for the collection of gas samples, which containersare capable of preserving the integrity of the gas sample for asubstantial, if not indefinite, length of time and which aresufficiently inexpensive that they may be disposed of after a single useat a cost substantially less than the present cost of using glasscontainers and Washing or cleaning them for reuse.

Containers formed in accordance with the broader aspects of the presentinvention are characterized by two sheets or layers of flexible sheetmaterial, joined together by seamed portions which define an expansiblestorage chamber and an inlet thereto. The inlet is elongated anddefined, at least in part, by a seamed portion of the sheet materialwhich also defines on its opposite side the storage chamber.

The container may be filled by inserting a tube through the inlet sothat pressurized fluid may be introduced into the storage chamber. Whenthe desired volume of fluid has been introduced into the storagechamber, the filling tube may then be retracted. It is a characteristicof the container that, upon retraction of the filling tube, theelongated inlet passageway, which is isolated from the storage chamberby the seamed portions of the sheet material, automatically sealsitself.

Particularly for the collection of gas samples, it is de sirable thatthe sheet material be impervious to all known gaseous elements, at leastof the sample. The best known material for this purpose is polyethyleneterephthalate. This resinous polymeric material further fulfills otherrequisite functions of the container in that it is flexible in orderthat the storage chamber may be expanded as a fluid sample is introducedtherein. Further, the material is relatively stiff, and thischaracteristic is believed to be a contributing factor to theeffectiveness of the sealing action which is obtained by the containerconfiguration.

The above and other related objects and features of the invention willbe apparent from a reading of the following description of thedisclosure found in the accompanying drawing and the novelty thereofpointed out in the appended claims.

In the drawing:

FIGURE 1 is a view of a container embodying the present invention;

FIGURE 2 is a fragmentary perspective view of the container seen inFIGURE 1 after a fluid sample has been introduced therein;

FIGURE 3 is a section, on an enlarged scale, taken on line III-III inFIGURE 2; and

FIGURE 4 is a section, also taken on line III-III in FGURE 2, whichillustrates the use of a tube for introduc ing a fluid sample into thecontainer.

Referring now to the drawing, a rectangularly shaped container 2 forreceiving and/or storing a fluid mixture and particularly a gaseousmixture is illustrated in FIG- URES 1-4. Specifically, container 2 iscomprised of two superposed sheets or layers of material 6 and 8 securedtogether by a seam 4 which extends around the peripheral marginal edgeportions of the layers. Additionally, the layers 6 and 8 are securedtogether by a seam 14 which is spaced from and generally parallel to aportion of peripheral seam 4. The seams 4 and 14 define an inflatablestorage chamber 10 and an inlet passageway 16 having an inlet port 12and an exit port 18 opening into the chamber 10.

As previously discussed, the present container is especially suited forreceiving and storing gaseous samples. Such containers are useful in theperformance of analytical tests on gas samples and, particularly, testson gaseous combustion products. For such tests to be successful, it isimportant to insure that the integrity of the gas sample compositionwill be preserved. It is characteristic of many materials otherwisesuitable for the layers 6, 8 to be impervious to some constituents of agiven gas sample while not to others. Of particular difficulty isobtaining a suitable material which is impervious to hydrogen.Polyethylene terephthalate resin has been found particularly effectiveand is preferred for purposes of preserving the gas sample integrity. Itis also recognized that material thickness can affect perviousness. Athickness of .005 inch has been found effective but thinner or thickerlayers could be used.

The seams 4, 14 of the container must effectively seal the layers 6, 8and may be formed by various methods, including sealingby heat, solventsor adhesives. Normally, it is preferred to use heat sealing because itis the least expensive method. In the case of the preferred material,special sealing techniques known to the art may be required.

To illustrate use of the container, FIGURE 1 shows schematically, afiller tube 20 connected to a source of pressurized fluid. The fillertube 20 is introduced into inlet passageway 16 (see also FIGURE 4)integral to the con- 3 tainer 2, by deflecting the layers 6 and 8 of thecontainer material which comprise the lips of the inlet port 12. Inorder to facilitate the introduction of the filler tube into the inletpassageway, one of the layers may be offset or notched, as at 22depicted in both FIGURES 1 and 2. The space between the tube 20 and thewalls of the inlet passageway 16 (FIGURE 4) provides a leakagepassageway to prevent overpressurization of the chamber 10. After thestorage chamber 10 is filled to a desired amount, as shown in FIGURE 2,the filler tube is retracted. The inlet passageway 16 will automaticallyreturn to the condition illustrated in FIGURE 3 and seal itself tothereby isolate the sample of gaseous material from the atmosphere.

The self-sealing properties of the passageway 16 are attributable toseveral factors. First to be noted is that the passageway 16 iselongated and isolated from the storage chamber 10 by the seam 14.

The relative stiffness of the preferred material is believed tocontribute to a self-sealing function. Deflection of the sheet materialwalls 6, 8, defining the inflated chamber 10, apparently constrict theexit port 18 to form the desired sealing action which is supplemented byother contact areas between the layers 6, 8 along the length of thepassageway 16. Further, with a relatively stiff material as thepreferred polyethylene terephthalate, a ratio of passageway length towidth of at least about 10:1 is preferred.

To withdraw the sample from the storage area, an extraction tube (notshown), similar to the tube 20, is inserted through the inlet port 12and the inlet passageway 16 and the exit port 18. As this is done, theexit port may be manually pinched to minimize escape or contamination ofthe sample until the extraction is ready to pass through the exit portto withdraw the sample. The container layers 6, 8 may then be pressedagainst the extraction as it passes through the exit and into thechamber 10. The chamber 10 may then be collapsed to discharge the fluidsample through the extraction tube.

The container thus formed and described above is a relativelyinexpensive item. For collection of gas samples, it may be disposed ofafter a single use at a cost substantially less than the cost of glasscontainers and their preparation for reuse.

While the embodiment of FIGURES 1 and 2 illustrate a generallyrectangularly configured container having an inlet port located in thevicinity of one of its corners, it should be understood that theinvention is not limited thereto and that other embodiments are withinthe present inventive concepts.

Having thus described the invention, what is claimed as novel anddesired to be secured by Letters Patent of the United States is:

1. A container for receiving and storing fluids, said containercomprising,

two superposed layers of flexible polyethylene terephthalate sheetmaterial joined together by seamed portions defining an inflatablestorage chamber and a passageway thereto,

said passageway being defined by elongated, generally parallel, spaced,sea-med portions isolating the inlet itself from internal fluidpressures in said storage chamber,

said passageway having an inlet at one end and an exit opening into saidchamber at its opposite end and further being characterized by the sheetmaterial layers defining same being normally contiguous at leastsubstantially throughout its length,

said layers defining said passageway being deflectable for the insertionof a tube to provide communication with said chamber and resilient to asealing position upon retraction of said tube.

2. A container for receiving and storing fluids as recited in claim 1wherein each of said layers of polyethylene terephthalate resin is of 5mil. gage thickness.

3. A container for receiving and storing fluids as recited in claim 1wherein the ratio of the length of said passageway to its width isapproximately 10:1.

4. A container as in claim 1 having a generally rec tangular outline andthe seamed portions are formed marginally of the periphery and include aseam extending inwardly from one edge to a point spaced from the seamedportion at the opposite edge, said seam being parallel to and spacedfrom the seamed portion of the adjacent edge to define the inletpassageway.

5. A container as in claim 4 wherein the polyethylene terephthalatesheet material has a thickness of approximately .005 inch,

the seamed portions are heat sealed,

said passageway has a length to width ratio of approximately 10:1 and,

one of the layers at the passageway inlet is offset to facilitateinsertion of a tube therein.

References Cited UNITED STATES PATENTS 2,719,100 9/1955 Banigan 229482,998,340 8/1961 Conway et al. 3,142,437 7/1964 Grant et a1 229-683,144,976 8/ 1964 Freshour 2297 FOREIGN PATENTS 980,859 1/1965 GreatBritain. 580,742 8/ 1958 Italy.

DAVID M. BOCKENEK, Primary Examiner.

1. A CONTAINER FOR RECEIVING AND STORING FLUIDS, SAID CONTAINERCOMPRISING, TWO SUPERPOSED LAYERS OF FLEXIBLE POLYETHYLENE TEREPHTHALATESHEET MATERIAL JOINED TOGETHER BY SEAMED PORTIONS DEFINING AN INFLATABLESTORAGE CHAMBER AND A PASSAGEWAY THERETO, SAID PASSAGEWAY BEING DEFINEDBY ELONGATED, GENERALLY PARALLEL, SPACED, SEAMED PORTIONS ISOLATING THEINLET ITSELF FROM INTERNAL FLUID PRESSURES IN SAID STORAGE CHAMBER, SAIDPASSAGEWAY HAVING AN INLET AT ONE END AND AN EXIT OPENING INTO SAIDCHAMBER AT ITS OPPOSITE END AND FURTHER BEING CHARACTERIZED BY THE SHEETMATERIAL LAYERS DEFINING SAME BEING NORMALLY CONTIGUOUS AT LEASTSUBSTANTIALLY THROUGHOUT ITS LENGTH, SAID LAYERS DEFINING SAIDPASSAGEWAY BEING DEFLECTABLE FOR THE INSERTION OF A TUBE TO PROVIDECOMMUNICATION WITH SAID CHAMBER AND RESILIENT TO A SEALING POSITION UPONRETRACTION OF SAID TUBE.